Prior art pickup trucks include a cab for carrying a driver and one or more passengers, as well as a cargo box behind the cab for carrying cargo. The cargo box is typically defined by a cargo floor, two sidewalls, and the back of the cab. The cargo box includes an opening at the rearward end to facilitate the loading and unloading of cargo onto the cargo floor. A tailgate is pivotably mounted to the end of the cargo box to selectively close the rearward opening thereof. Cargo placed on the cargo floor adjacent the opening may shift forward during movement of the pickup truck, away from the opening.
Cargo boxes are typically open and exposed from the exterior. In order to secure personal items in the cargo box, a separate, lockable tool box is sometimes placed in the front portion of the cargo box. However, the tool box reduces the length of the cargo box available for cargo.